How Much DEF Are You Using In Miles?

[TCDiesel]

Ah. I see my mistake. But if you do the same math with gsbrockman's numbers..... His is close to 3 oz per 11.1 mile. So it is not an unreasonable amount of def.

Hmm. I would check the math again....

 

[AH64ID]

That’s why the dose rate percentage is more important that the mpg.

 

[Newsa]

Checking........

Hmm. I would check the math again....

144.301 gals x 128 oz/gal. /68722 miles × 11.1 miles.

2.98 oz/ 11.1 miles

Did i get it right?

 

[TCDiesel]

Ok Let see If I got it Right 144 gallons X 128= 18432 OZ
68722 Miles divided by 18432 OZ = 3.72 OZ PM

 

[Newsa]

Ok Let see If I got it Right 144 gallons X 128= 18432 OZ
68722 Miles divided by 18432 OZ = 3.72 OZ PM

Nope you're confusing miles/oz with oz/mile?

 

[TCDiesel]

Nope you're confusing miles/oz with oz/mile?

You are correct, I just re-did the math.

 

[Boaring1961]

I've had DEF rates of 3.95 mi/ounce (2,317 mpg) and 2.88 mi/ounce (1,692 mpg).

 

[Dan_69GTX]

The bottle is always empty before I get somewhere so I'm not sure of the dose rate. Then, I have to walk back to the fridge w/o a bottle so I'm not sure how that factors into the calculations.

I'm guessing common core stuff....vs common rail.....

Wait - what were we talking about?!?......Oh yea - need another bottle....

 

[Signal73]

I used about a gallon to a tank of fuel towing my camper through hilly VT mass and into CT this
past week.

 

[JET]

I just checked my log, and I have added DEF 24 times, so that is 60 gallons in about 96,000 miles, or about 12.5 miles per ounce.

 

[gsbrockman]

Throwing in some more numbers into the mix.....

My last DEF fill was 8.978 gallons. Fuel consumed was 345.909 gallons. Miles traveled was 3,615. The DEF ratio comes in at 2.5954%. Average miles per gallon of DEF was 402.65 mpg. Averages miles per gallon on #2 was 10.451.

I have some other figures I can somewhat readily put together through 171,382 miles if there’s any interest.

 

[JET]

Good evening guys. An update for my previous post.
I just re-checked my log, and I have added DEF 24 times, so that is 60 gallons in about 96,000 miles, or about 12.5 miles per ounce. In that same amount of time I have bought 5646.5 gallons of fuel for a little over 16 mpg combined driving.

 

[Newsa]

Good evening guys. An update for my previous post.
I just re-checked my log, and I have added DEF 24 times, so that is 60 gallons in about 96,000 miles, or about 12.5 miles per ounce. In that same amount of time I have bought 5646.5 gallons of fuel for a little over 16 mpg combined driving.

That is only 1.06 % Def use as compared to fuel usage. That is about half of what most engine manufactures and emissions design teams estimate.

Maybe if your def sits in the tank, the water evaporates out and it exceeds 40% Urea/water (instead of the standard 32.5%?) concentration and the injector only works half as hard?

Edit: Another possible scenario is that some of those miles, your DEF is frozen and you are using fuel, but no DEF? Those cold morning start ups can use more fuel as the engine trys to get to operating temps.

 

[AH64ID]

I topped off DEF before and after elk hunting.

I used DEF at a slightly higher rate during those miles, I also got considerably lower mileage.

1626 miles with 3.367 gallons of DEF used and 163.627 gallons of diesel burned. 2.1% dosage rate, 483 mpg DEF, and 9.9 mpg diesel. There was some towing in there at 24K GCW, but most of the low mileage was low speed forest service roads in 1/2 and over 115 miles with 4 chains on.

 

[Cummins12V98]

I used about a full tank towing 35k combined from NW WA to SoCal 1,300 miles along I-5. Lot's of 6% grades.

 

[gsbrockman]

I used about a full tank towing 35k combined from NW WA to SoCal 1,300 miles along I-5. Lot's of 6% grades.

A specific amount of gallons of DEF consumed, diesel fuel consumed, and an exact distance will make your post more meaningful in relation to this thread’s actual title.

 

[DonFitzwater]

I’m averaging 850 mpg of DEF.

 

[AH64ID]

I’m averaging 850 mpg of DEF.

Do you know what the rate is relative to diesel?

 

[DonFitzwater]

Do you know what the rate is relative to diesel?

Not off the top of my head but I’ll see if I can pull my used gallons of fuel numbers up next time I have the truck out.

 

[Cummins12V98]

A specific amount of gallons of DEF consumed, diesel fuel consumed, and an exact distance will make your post more meaningful in relation to this thread’s actual title.

A specific amount of gallons of DEF consumed, diesel fuel consumed, and an exact distance will make your post more meaningful in relation to this thread’s actual title.

BUT, BUT that takes sum mathmatics skilZ.

1,300 miles with about 145G diesel used. Honestly don't know the tanks capacity???